The invention relates to devices and method for producing focused electric fields, and also to using such devices and methods to sense naturally occurring electric signals in human nerve cells and to produce controlled electrical signals in human nerve cells.
Various techniques have been used to sense signals produced in human nerve cells. For example, "invasive" procedures involving insertion of electrical probes into nerve cells to measure signals therein have been practiced. Such procedures are obviously undesirable, as they risk injury to the person (or animal) involved. Devices using skin contact electrodes have been utilized to sense the level of electrical activity in the brain. However, precise measurement of electrical activity in a single nerve cell cannot be accomplished using this method. Invasive probes and electrodes that contact the skin of a person have been used to produce electrical signals in nerves, but are subject to the same shortcomings as use of the above techniques for sensing nerve signals. There would undoubtedly be numerous beneficial uses for any devices and techniques that would have the capability of accurately sensing electrical signals in individual nerve cells and introducing accurately controlled signals from external sources into nerve cells without the necessity for invasive techniques that penetrate the surface of the nerve cell.
Therefore, it is an object of the invention to provide a device and method for accurately sensing a normally occurring electrical signal in a nerve of a human or animal without necessitating any invasion of the nerve by any apparatus.
It is another object of the invention to provide a device and method for accurately producing a controlled electric signal in a nerve of a human or animal without necessitating invasion of the nerve by any apparatus or surgical procedure.
It is another object of the invention to provide a device and method for measuring electrical signals in a human or animal brain.
Conventional hearing aids operate by amplifying the intensity of sound in a patient's ear to very high levels that can be heard by persons with damaged hearing systems. However, the fidelity and accuracy of the sounds actually heard by the hearing impaired or deaf person are often quite poor, depending on the nature of the person's hearing impairment. Despite improvements that have been made in hearing technology, there remains a need for a method and apparatus for improving the quality of sounds heard under various conditions by hearing and hearing impaired persons alike.
Therefore, it is another object of the invention to provide an improved hearing aid apparatus and method.
It is another object of the invention to provide an improved method and apparatus for producing and utilizing focused electric fields.